Certified Tumor Registrar (CTR) Practice Exam

Peristalsis is a physiological function of which part of the digestive system?

1. Stomach

2. Muscularis propria of the intestines

3. Esophagus

4. Duodenum

The correct answer is: Muscularis propria of the intestines

Peristalsis is a coordinated, rhythmic contraction of smooth muscle that is crucial for the movement of food and waste through the gastrointestinal tract. The muscularis propria, also known as the muscularis layer, consists of two layers of muscle (an inner circular layer and an outer longitudinal layer) that work together to facilitate peristalsis. This muscular action helps propel contents through the intestines, aiding in digestion and absorption. While the stomach, esophagus, and duodenum all have muscle layers that facilitate movement, it is the muscularis propria of the intestines that is the specific focus of peristalsis as it relates to the primary segment of this coordinated activity. Each of these sections of the digestive system contributes to the process, but the muscularis propria of the intestines is particularly recognized for its role in continuing the peristaltic movement established in the esophagus after swallowing food. This distinction is essential for understanding how food is processed through the entire digestive system.